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1.
Chemosphere ; 287(Pt 4): 132406, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34597649

RESUMO

Being analogue to arsenic (As), phosphorus (P) may affect As dynamics in soil and toxicity to plants depending upon many soil and plant factors. Two sets of experiments were conducted to determine the effect of P on As fractionation in soils, its accumulation by plants and subsequent impact on growth, yield and physiological characteristics of sunflower (Helianthus annuus L.). Experimental plan comprised of two As levels (60 and 120 mg As kg-1 soil), four P (0-5-10-20 g phosphate rock kg-1 soil) and three textural types (sandy, loamy and clayey) with three replications. Among different As fractions determined, labile, calcium-bound, organic matter-bound and residual As increased while iron-bound and aluminum-bound As decreased with increasing P in all the three textural types. Labile-As percentage increased in the presence of P by 16.9-48.0% at As60 while 36.0-68.1% at As120 in sandy, 19.1-64.0% at As60 while 11.5-52.3% at As120 in loamy, and 21.8-58.2% at As60 while 22.3-70.0% at As120 in clayey soil compared to respective As treatment without P. Arsenic accumulation in plant tissues at both contamination levels declined with P addition as evidenced by lower bioconcentration factor. Phosphorus mitigated the As-induced oxidative stress expressed in term of reduced hydrogen peroxide, malondialdehyde while increased glutathione, and consequently improved the achene yield. Although, P increased As solubility in soil but restricted its translocation to plant, leading to reversal of oxidative damage, and improved sunflower growth and yield in all the three soil textural types, more profound effect at highest P level and in sandy texture.


Assuntos
Arsênio , Helianthus , Poluentes do Solo , Arsênio/análise , Arsênio/toxicidade , Fósforo , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
2.
Sci Total Environ ; 805: 150337, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34543788

RESUMO

Globally, agriculture sector is the significant source of greenhouse gases (GHGs) emissions into the atmosphere. To achieve the goal of limiting or mitigating these emissions, a rigorous abatement strategy with an additional focus on improving crop productivity is now imperative. Replacing traditional agriculture with soil conservation-based farming can have numerous ecological benefits. However, most assessments only consider improvements in soil properties and crop productivity, and often preclude the quantitative impact analysis on GHGs emissions. Here, we conducted a meta-analysis to evaluate crop productivity (i.e., biomass, grain, total yield) and GHGs emissions (i.e., CO2, N2O, CH4) for three major soil conservation practices i.e., no-tillage, manures, and biochar. We also examined the yield potential of three major cereal crops (i.e., wheat, rice, maize) and their significance in mitigating GHGs emissions. None of the manures were able to reduce GHGs emissions, with poultry manure being the largest contributor to all GHGs emissions. However, pig-manure had the greatest impact on crop yield while emitting the least CO2 emissions. Use of biochar showed a strong coupling effect between reduction of GHGs (i.e., CH4 by -37%; N2O by -25%; CO2 by -5%) and the increase in crop productivity. In contrast, no-tillage resulted in higher GHGs emissions with only a marginal increase in grain yield. Depending on crop type, all cereal crops showed varied degrees of GHGs mitigation under biochar application, with wheat responding most strongly due to the additional yield increment. The addition of biochar significantly reduced CO2 and N2O emissions under both rainfed and irrigated conditions, although CH4 reductions were identical in both agroecosystems. Interestingly, the use of biochar resulted in a greater yield benefit in rainfed than in irrigated agriculture. Despite significant GHGs emissions, manure application contributed to higher crop yields, regardless of soil type or agroecosystem. Moreover, no-tillage showed a significant reduction in CH4 and N2O emissions under rainfed and irrigated conditions. Notably , biochar application in coarse while no-till in fine textured soils contributed to N2O mitigation. Most importantly, effectiveness of no-tillage as a countermeasure to GHGs emissions while providing yield benefits is inconsistent. Overall, the decision to use farm manures should be reconsidered due to higher GHGs emissions. We conclude that the use of biochar could be an ideal way to reduce GHGs emissions. However, further understanding of the underlying mechanisms and processes affecting GHGs emissions is needed to better understand the feedback effects in conservation agriculture.


Assuntos
Gases de Efeito Estufa , Agricultura , Animais , Produção Agrícola , Fertilizantes/análise , Esterco , Metano/análise , Óxido Nitroso/análise , Solo , Suínos
3.
J Hazard Mater ; : 127891, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34848065

RESUMO

Arsenic (As) is a highly toxic contaminant in the environment. Although both inorganic and organic types of arsenic exist in the environment, the most common inorganic forms of As that adversely affect plants are arsenite (As III) and arsenate (As V). Despite no evidence for As being essential for plant growth, exposure of roots to this element can cause its uptake primarily via transporters responsible for the transport of essential mineral nutrients. Arsenic exposure even at low concentrations disturbs the plant normal functioning via excessive generation of reactive oxygen species, a condition known as oxidative stress leading to an imbalance in the redox system of the plant. This is associated with considerable damage to the cell components thereby impairing normal cellular functions and activation of several cell survival and cell death pathways. To counteract this oxidative disorder, plants possess natural defense mechanisms such as chemical species and enzymatic antioxidants. This review considers how different types of antioxidants participate in the oxidative defense mechanism to alleviate As stress in plants. Since the underlying phenomena of oxidative stress tolerance are not yet fully elucidated, the potential for "Omics" technologies to uncover molecular mechanisms are discussed. Various strategies to improve As-induced oxidative tolerance in plants such as exogenous supplementation of effective growth regulators, protectant chemicals, transgenic approaches, and genome editing are also discussed thoroughly in this review.

4.
Front Pharmacol ; 12: 708618, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34776946

RESUMO

Sphaeranthus indicus L. is a medicinal herb having widespread traditional uses for treating common ailments. The present research work aims to explore the in-depth phytochemical composition and in vitro reactivity of six different polarity solvents (methanol, n-hexane, benzene, chloroform, ethyl acetate, and n-butanol) extracts/fractions of S. indicus flowers. The phytochemical composition was accomplished by determining total bioactive contents, HPLC-PDA polyphenolic quantification, and UHPLC-MS secondary metabolomics. The reactivity of the phenolic compounds was tested through the following biochemical assays: antioxidant (DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum, and metal chelation) and enzyme inhibition (AChE, BChE, α-glucosidase, α-amylase, urease, and tyrosinase) assays were performed. The methanol extract showed the highest values for phenolic (94.07 mg GAE/g extract) and flavonoid (78.7 mg QE/g extract) contents and was also the most active for α-glucosidase inhibition as well as radical scavenging and reducing power potential. HPLC-PDA analysis quantified rutin, naringenin, chlorogenic acid, 3-hydroxybenzoic acid, gallic acid, and epicatechin in a significant amount. UHPLC-MS analysis of methanol and ethyl acetate extracts revealed the presence of well-known phytocompounds; most of these were phenolic, flavonoid, and glycoside derivatives. The ethyl acetate fraction exhibited the highest inhibition against tyrosinase and urease, while the n-hexane fraction was most active for α-amylase. Moreover, principal component analysis highlighted the positive correlation between bioactive compounds and the tested extracts. Overall, S. indicus flower extracts were found to contain important phytochemicals, hence could be further explored to discover novel bioactive compounds that could be a valid starting point for future pharmaceutical and nutraceuticals applications.

5.
J Med Cases ; 12(11): 446-450, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34804304

RESUMO

Oral contraceptive pills (OCPs) have a known prothrombotic effect. Obliterative portal venopathy (OPV) can be seen in patients with underlying hypercoagulability. We present a case of a 19-year-old female patient taking OCPs who presented with obstructive jaundice. Her main concern was pruritis. An extensive workup was done to reach a diagnosis but it came back negative. A liver biopsy showed OPV. This was thought secondary to her OCP use. Her OCPs were discontinued which resulted in a complete resolution of her symptoms and laboratory abnormalities. Cases with a direct relationship between OPV and OCP use are extremely rare. More studies are required to establish a correlation between OPV and OCPs. OPV should be considered in the differential diagnosis among patients with obstructive jaundice without an obvious cause, especially in patients taking OCPs. Treatment is stopping the OCPs with close follow-up to confirm disease resolution.

6.
J Med Cases ; 12(11): 464-467, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34804308

RESUMO

Gastric outlet obstruction can occur secondary to intrinsic or extrinsic pathology. Historically peptic ulcer disease was the most common cause of gastric outlet obstruction but now malignancy-associated disease process is more common. Gastric outlet obstruction from mucosal ischemia caused by embolization of gastroduodenal artery is unheard of. This is due to the extensive blood supply of the stomach. We present an unusual presentation of gastric outlet obstruction in a patient with recent embolization of pancreatitis-induced pseudoaneurysm of the gastroduodenal artery. The diagnosis was confirmed with esophagogastroduodenoscopy, computed tomography, and upper gastrointestinal series. The case was managed conservatively with a clear liquid diet and proton pump inhibitors. Repeat upper endoscopies at 1 and 6 months after presentation confirmed disease resolution. No guidelines exist on the management of such cases due to the rarity of the disease.

7.
Front Psychol ; 12: 711439, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34759861

RESUMO

This study investigated the relationships among emotional intelligence (EI), relational engagement (RE), and cognitive outcomes (COs). A survey questionnaire containing 34 statements was completed by 338 undergraduate students from the four universities of China, with responses recorded on a 7-point Likert-type scale. The relationships were examined using the partial least squares structural equation modeling. The findings showed that EI influenced the COs directly and indirectly during the pandemic. In the forms of self-regulation (SR) and social skills (SS), the high levels of EI improved the COs of the students. Further, the aspects of EI, such as SR, self-awareness (SA), empathy (E), motivation (M), and SS were found to improve the RE of the students. The RE was positively correlated with the COs, indicating its potential for improving critical thinking among university students. Finally, the RE was a key mediator of the relationship between the EI and COs. It is concluded that the students with higher levels of EI and RE may achieve better COs. The implications of the research and suggestions for future studies are also discussed.

8.
Pak J Pharm Sci ; 34(5(Supplementary)): 1989-1994, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34836871

RESUMO

The objective of this study was to deal with the evaluation of 7-(2-(benzylideneamino)-2-(cyclohexa-1,4-dienyl)acetamido)-3-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid based schiff bases as a new class of enzyme inhibitors. In this connection, a series of Schiff bases of cephradine with substituted aromatic aldehydes was synthesized and characterized using FTIR, 1HNMR and 13CNMR. The in-vitro biological activities including free radical scavenging potential using DPPH assay, acetyl cholinesterase and butyryl cholinesterase inhibition potential were evaluated. Two compounds of the series 1g and 1h were found to be active against AChE whereas no derivative was active against BChE while the whole series showed excellent 1, 1-diphenyl-2-picrylhydrazyl scavenging activity. All the synthesized compounds were found to be non-toxic and present passive gastrointestinal absorption. Furthermore, the study suggests that the synthesized cephradine derivatives exhibit inhibitory potential against different biologically relevant enzyme targets.

9.
Cell Mol Biol (Noisy-le-grand) ; 67(1): 159-164, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-34817352

RESUMO

Aim of the present study was to determine the In-vitro antibacterial activity of ethanolic extract of E. globulus leaves against common multidrug resistant poultry pathogens. Phytochemical analysis through HPLC revealed that kaempeferol (7.315min) followed by querecetin (6.655min) and myrecetin (3.655min). Percent area of kaempeferol (6826.88%) was highest, followed by myrecetin (5516.22%) and querecetin (163.748%). Phytochemical investigation of ethanolic extract of E. globulus leaves through GCMS showed highest retention time (min) α-pinene (20.43) and α-terpineol (20.15) accompanied by spathulenol (11.97), piperitone (11.04). The ethanolic extracts of E. globulus leaves showed a highest zone of inhibition against S. pullorum SP6; 20.64± 2.08, E. coli SE 12; 19.75± 2.83, C. perfringens type A (CPM38-01); 19.46± 2.02. The highest level of MIC of E. globulus noted were against S. gallinarum S22; 133.37±53.294, S. gallinarum S1; 130.20±45.10, S. gallinarum S4; 129.47±24.182, S. gallinarum S3; 126.83±72.392. In conclusion, the study confirmed that the ethanolic extract of E. globulus is composed of active ingredients having antibacterial activity and can be referred as an alternate to antibiotics.

10.
Cell Mol Biol (Noisy-le-grand) ; 67(1): 153-158, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-34817353

RESUMO

The present study was designed to evaluate the antimicrobial activity of E. globulus leaves in broiler chicks. Total (n=255) day-old chicks were segregated into five groups i.e. Pathogenic E. coli, S. pullorum, S. gallinarum and C. perfringens type A and control negative group. Each bacterial challenged (1x 107 CFU) group was divided into control positive, antibiotic, probiotic and E. globulus group. Experimental birds were exposed to E. coli, S. pullorum, S. gallinarum and C. perfringens type A at different ages. At 35th day of experiment the log reduction for each group was determined. The highest log reduction in E. coli and C. perfringens Type A colonies count were found in E. globulus (3.26) (2.33) treated group followed by antibiotic (2.85) (1.59) and probiotic (2.84) (1.50) respectively. The log reduction in S. pullorum colonies count was highest in E. globulus (2.50) followed by probiotic (2.24) and antibiotic (2.16). The S. gallinarum colonies count log reduction was found highest for antibiotic (2.84) followed by probiotic (2.48) and E. globulus group. The results of in-vivo experiment revealed that ethanolic extract of E. globulus has antibacterial activity and it can be used as a replacement to low level of antibiotics added in poultry feed.

11.
Dose Response ; 19(4): 15593258211055026, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34819814

RESUMO

Choline chloride (CC) application enhanced the tolerance of cluster bean (Cyamopsis tetragonoloba L.) against salinity stress. The aim of the study was to determine the protective role of CC on plant growth, photosynthesis, and biochemical indicators of oxidative stress. The seeds of BR-99 (tolerant) and BR-2017 (sensitive) were surface sterilized and sown in plastic pots containing river sandy soil. The design of the experiments was completely randomized with 4 replicates per treatment. Three weeks after germination, salinity (150 mM) was imposed. Then plants were sprayed with different concentrations of CC (3, 5, and 10 mM), while normal plants were sprayed with distilled water. Salinity decreased growth attributes, relative water contents, photosynthetic attributes, total soluble proteins, total free amino acids, phenolic, flavonoids, ascorbic acid, proline, and glycine betaine and increased the levels of oxidative stress indicators. However, the application of CC (particularly 5 mM) improved growth attributes, photosynthetic pigments, and activities of antioxidant compounds by reducing the levels of H2O2, malondialdehyde in salt-stressed plants in both cluster bean varieties. BR-99 variety showed more tolerance to salinity stress than that of BR-2017 in the form of greater oxidative defense and osmotic adjustment and clear from greater plant dry masses. Thus, our results showed that the application of CC (5 mM) is an efficient strategy for field use in the areas, where salt stress soils limit agriculture production.

12.
Artigo em Inglês | MEDLINE | ID: mdl-34836654

RESUMO

From environmental waste to energy storage, waste boxes converted into conductive electrodes to further grow active materials has been an interesting way of upcycling. In this study, we transformed waste boxes of KIMTECH Kimwipes® into conductive f-MWCNTs light and flexible substrate (LFS) as current collectors. Then, undoped and P-doped active materials consisting of layered quadruple hydroxides (LQH) was successfully grown on the conductive f-MWCNTs/LFS. Specifically, P-doped f-MWCNTs/LQH demonstrates 1.8 times the capacitance of an undoped f-MWCNTs/LQH. Such conversion of waste boxes not only offers a useful way of reusing waste papers which commonly ends in landfills, but the inexpensive method also offers an extreme way of cutting cost in developing conductive substrates. Also, the effective strategy of synthesizing active materials on the conductive f-MWCNTs/LFS paves its way as potential cheap electrodes of the future generation.

13.
Plants (Basel) ; 10(11)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34834903

RESUMO

A study was carried out to evaluate the effectiveness of sugar beet extract (SBE) and glycine betaine (GB) in mitigating the adverse effects of drought stress on two maize cultivars. Seeds (caryopses) of two maize cultivars, Sadaf (drought-tolerant) and Sultan (drought-sensitive) were sown in plastic pots. Plants were subjected to different (100%, 75% and 60% field capacity (FC)) water regimes. Then, different levels of SBE (3% and 4%) and GB (3.65 and 3.84 g/L) were applied as a foliar spray after 30 days of water deficit stress. Drought stress significantly decreased plant growth and yield attributes, chlorophyll pigments, while it increased relative membrane permeability (RMP), levels of osmolytes (GB and proline), malondialdehyde (MDA), total phenolics and ascorbic acid as well as the activities of superoxide dismutase (SOD) and peroxidase (POD) enzymes in both maize cultivars. Exogenous application via foliar spray with SBR or GB improved plant growth and yield attributes, chlorophyll pigments, osmolyte concentration, total phenolics, ascorbic acid and the activities of reactive oxygen species (ROS) scavenging enzymes (SOD, POD and catalase; CAT), but reduced leaf RMP and MDA concentration. The results obtained in this study exhibit the role of foliar-applied biostimulants (natural and synthetic compounds) in enhancing the growth and yield of maize cultivars by upregulating the oxidative defense system and osmoprotectant accumulation under water deficit conditions.

14.
iScience ; 24(12): 103388, 2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34841228

RESUMO

Trifluoromethylated molecules have gained privileged recognition among the medicinal and pharmaceutical chemists. Sustainable photoredox- and electrochemical processes were employed to facilitate the relatively less explored radical cross-electrophile coupling to access trifluoromethyl- and allyl-substituted tert-alcohols. Reactions proceed through trifluoromethyl ketyl radical and allyl radical intermediates, which undergo challenging radical-radical cross-coupling. The developed transformations are mild and chemo-selective to give cross-coupled products and deliver a wide range of valuable trifluoromethyl- and allyl-containing tertiary alcohols. Both processes can also be applied for the synthesis of amine variant containing trifluoromethyl and allyl moiety, which is considered as amide bioisostere.

15.
PLoS One ; 16(11): e0254906, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34843496

RESUMO

Now-a-days, plant-based extracts, as a cheap source of growth activators, are being widely used to treat plants grown under extreme climatic conditions. So, a trial was conducted to assess the response of two maize (Zea mays L.) varieties, Sadaf (drought tolerant) and Sultan (drought sensitive) to foliar-applied sugar beet extract (SBE) under varying water-deficit conditions. Different SBE (control, 1%, 2%, 3% & 4%) levels were used in this study, and plants were exposed to water-deficit [(75% and 60% of field capacity (FC)] and control (100% FC) conditions. It was observed that root and shoot dry weights (growth), total soluble proteins, RWC-relative water contents, total phenolics, chlorophyll pigments and leaf area per plant decreased under different water stress regimes. While, proline, malondialdehyde (MDA), RMP-relative membrane permeability, H2O2-hydrogen peroxide and the activities of antioxidant enzymes [CAT-catalase, POD-peroxidase and SOD-superoxide dismutase] were found to be improved in water stress affected maize plants. Exogenous application of varying levels of SBE ameliorated the negative effects of water-deficit stress by enhancing the growth attributes, photosynthetic pigments, RWC, proline, glycinebetaine (GB), activities of POD and CAT enzymes and levels of total phenolics, whereas it reduced the lipid peroxidation in both maize varieties under varying water stress levels. It was noted that 3% and 4% levels of SBE were more effective than the other levels used in enhancing the growth as well as other characteristics of the maize varieties. Overall, the sugar beet extract proved to be beneficial for improving growth and metabolism of maize plants exposed to water stress.

17.
Ecotoxicol Environ Saf ; 227: 112914, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34678629

RESUMO

Few data are available regarding comprehensive or quantitative assessment of fish feed considering both the environmental and feeding impacts. Aiming to fill the gap, an experimental study to investigate the effects of three fish feeds on concentrations of nutrients and crucian carp (Carassius carassius) growth was conducted in laboratory aquariums in the presence and absence of prometryn. Results showed that weight gain rates of crucian carp treated with Tong Wei (TW) feed were 106.3% and 2.0% higher than that of Zhong Shan (ZS) and Zhong Liang (ZL) feeds, a possible explanation was that the quality of protein in TW feed was highest as evidenced by the protein efficiency ratios. Meanwhile, TW feed posed relatively lighter effects on water qualities (between ZL and ZS). Prometryn significantly inhibited the growth of crucian carp and thus affected concentrations of nutrients in water indirectly. The relationships between weight gain rates of fish and concentrations of nutrients in water (R2 = 0.929-0.990) were developed. In sum, this study suggested that it is realizable to obtain better fish growth performance with lesser degrading effects on water qualities by producing and selecting appropriate feed regardless of prometryn existence, and the developed equations could be used as a basis for future studies.


Assuntos
Carpas , Prometrina , Animais , Qualidade da Água
18.
Chemosphere ; : 132678, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34710460

RESUMO

Soil salinity is one of the most pernicious environmental hazards affecting crop growth and productivity in arid and semi-arid climates. In saline soils, the crop plants encounter nutrients deficient conditions mainly due to antagonistic affinity of sodium (Na+) and chloride (Cl-). The accumulation of salts in the rhizosphere restricts plant growth, the severity of which depends on the source and concentration of the salt. Therefore, we hypothesized that sodium containing salts could have toxic effects on maize plants either in a single or in combined form. To evaluate the interactive effect of sodium salts on plant growth, ionic homeostasis, and seed quality attributes, a pot study was performed using maize as a test plant at the research area of the College of Agriculture, University of Sargodha. Selected salts including, NaCl, Na2SO4 and their combination (NaCl + Na2SO4), were applied in equal ratio for different salinity levels (7, 10, 13 and 16 dS m-1) and the untreated control. The results show that all the measured growth, yield, biochemical and quality attributes of maize were negatively affected with increasing concentration of all the salt sources; however, severity of these effects were more intense when NaCl was applied at all salinity levels. It is concluded that all salts (NaCl, Na2SO4 and NaCl + Na2SO4) had negative effects on biochemical, qualitative, growth and yield characteristics of maize plant. Most importantly, NaCl was found to be more harmful compared to Na2SO4 and mixtures of both salts due to the dominance of Na+ and Cl-ions. Among all salinity levels, the more detrimental effects of NaCl occurred at salinity level of 16 dS m-1.

19.
Artigo em Inglês | MEDLINE | ID: mdl-34617216

RESUMO

This study's aim was to investigate iron (Fe) and zinc (Zn) concentration in the soil, forage crops, and sheep blood with respect to the seasonal availability of these metals. Soil, forage, and sheep blood samples were sampled from five different locations in Chakwal (Pidh, Tobar, Ratoccha, Choa Saiden Shah-Kalar Kahar road, and Choa Saiden Shan-Chakwal Road) during two seasons, i.e., winter and summer. All the samples were processed through wet acid digestion for evaluation of metal contents. Because of proximity of site-1 and site-2 to coal mines, higher Fe concentration was observed than Zn. Overall, varied Fe concentrations obtained in soil were 12.95-24.31 mg/kg, 1.29-9.61 mg/kg in forage and 1.17-24 mg/l in blood, whereas Zn values were 1.04-31.9 mg/kg, 1.96-7.02 mg/kg, and 0.16-6.52 mg/l for soil, forages, and blood respectively. The pollution load index value for both Fe (0.01-0.14 mg/kg) and Zn (0.02-0.72 mg/kg) was lesser than 1. Bio-concentration (0.09-2.64mg/kg) and enrichment factor (0.08-7.51 mg/kg) were showing efficient transfer of metals through the food chain. Daily intake and health risk index values of iron were ranged from 0.01 to 1.1 mg/kg/day and 0.02 to 1.05 mg/kg/day. There was a probable chance of upsurge in metal values in coming years due to continued mining activities. Anthropogenic input, mainly mining activities in the study area, have increased the Fe and Zn content in the environment which can ultimately find their way up the food chain, thereby risking the health of grazing livestock.

20.
Psychol Res Behav Manag ; 14: 1525-1541, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34629910

RESUMO

Blended Learning (BL) is one of the most used methods in education to promote active learning and enhance students' learning outcomes. Although BL has existed for over a decade, there are still several challenges associated with it. For instance, the teachers' and students' individual differences, such as their behaviors and attitudes, might impact their adoption of BL. These challenges are further exacerbated by the COVID-19 pandemic, as schools and universities had to combine both online and offline courses to keep up with health regulations. This study conducts a systematic review of systematic reviews on BL, based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, to identify BL trends, gaps and future directions. The obtained findings highlight that BL was mostly investigated in higher education and targeted students in the first place. Additionally, most of the BL research is coming from developed countries, calling for cross-collaborations to facilitate BL adoption in developing countries in particular. Furthermore, a lack of ICT skills and infrastructure are the most encountered challenges by teachers, students and institutions. The findings of this study can create a roadmap to facilitate the adoption of BL. The findings of this study could facilitate the design and adoption of BL which is one of the possible solutions to face major health challenges, such as the COVID-19 pandemic.

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